Whale WH/WI0802, How-To Manual, Page: 25 / 32

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Water Heater
4.8 Thermistor check and replacement AK1208/AK1210, AK1209/AK1211
The thermistor can be assessed by unplugging the device from the PCB as indicated. To access the
PCB please see Chapter 4.6.
Figure 16 – Thermistor assessment and replacement
4.9 Replacement of ignition electrode AK1220, AK1221
A number of symptoms can indicate that the ignition electrode requires replacement:
- failure to light despite audible spark generator operation
– cable damage, electrode wear
- weak spark and issue with flame sensing signal – cable, connection issue
- initial start-up of burner with subsequent closing of solenoid and flame extinguishing – electrode
wear
Figure 17 – Replacement of ignition electrode
The Thermistor can be checked without removing it from the Water Heater. It can be checked by unplugging it from
the PCB following the steps shown below.
- remove thermistor plug from PCB.
- measure resistance of Thermistor (app.
11.5k

@ ambient temperature)
- plug thermistor back into PCB if ok, or
replace thermistor if faulty.
- to replace thermistor:
- screw thermistor into Heater housing.
- refit thermistor plug to PCB.
- re-assemble front cover.
NOTE:
The Thermistor stud on the Water Heater can be either M5 or
M6. Measure the hex head of the Thermistor bolt to choose the
correct spare part.
1 2
3
! Ensure product is electrically isolated before opening the cover.
-remove cover and insulation as indicated in chapters 3.6 and 3.7
-Note: solenoid can be tested by applying 12V DC across its terminals
- unscrew ignition electrode
- should nut at the back spin,
support with screwdriver as shown
(not applicable when self-tapping
screw is used)
- the nut can remain inside the unit
(not applicable when self-tapping
screw is used)
- cut cable ties at indicated positions
- care is to be taken not to damage
adjacent wires when cutting cable
tie tails
1
2 3